In a semiconductor production process, particles and defects such as scratches on a surface of a semiconductor substrate (wafer) cause failure such as insufficient insulation, short, and the like of wiring formed on the wafer and also cause insufficient insulation of a capacitor and breakage of a gate oxide film and the like. Therefore, in the semiconductor production process, it is important to detect a defect on a surface of a wafer and feedback the defect to the semiconductor production process.
A so-called inspection apparatus detects such a defect. As an example of the inspection apparatus, there is an optical inspection apparatus that detects a defect on a substrate by irradiating a substrate with light and detecting scattered light thereof. The optical inspection apparatus is broadly classified into two types, i.e., a surface inspection apparatus for inspecting a mirror wafer and a patterned wafer inspection apparatus for inspecting a wafer on which a circuit pattern is formed.
In particular, in a case of the mirror wafer inspection apparatus, it is known that inspection is carried out by linearly moving a wafer while rotating the wafer with respect to light. The following PTLs 1-8 are cited as conventional arts regarding an inspection apparatus and draft control.